1. Field of the Invention
The present invention relates to the field of the fight against the pirating of decoders for accessing multimedia digital data. It relates more particularly to a process for the remote deactivation of such a decoder as well as to a decoder comprising means of remote deactivation.
2. Description of the Related Art
The operators broadcasting pay audiovisual programmes customarily provide the users who wish to receive these programmes with decoders allowing them to access the same by paying a subscription. The digital data constituting the programmes are indeed usually transmitted in encrypted form so that the users who do not have the decoder cannot access the same. The decoder contains in particular means for decrypting and for decoding the digital data. More precisely, the decoder generally comprises a chip card reader into which is inserted a card which contains a software module as well as one or more cryptographic keys necessary for the decrypting of the data. The chip card also generally contains information regarding the rights acquired by the user of the decoder (for example which channels are accessible to the user, for what duration, etc.).
When a user no longer wishes to pay to receive the programmes from an operator, he must in principle return his decoder to the operator or to an intermediary in charge of installing the decoders. Operators are nevertheless being increasingly confronted with a problem of pirating of their decoders. Indeed, certain users suspend their subscription but do not give back their decoder. They subsequently procure pirate chip cards giving extended rights of access to the programmes broadcast by the operator. Certain decoders are even stolen from the installers' vans so as likewise to be used with pirate chip cards.